In machines for the blowing of, for example, plastic bottles, use has hitherto been made of normal compressed air at approximately room temperature for blowing the objects into molds intended for the blow-molding. In attempts to increase production output rate, certain attempts have been made to use cooled nitrogen gas or carbon dioxide, but the production output rate increases thus attained have not been sufficient to outweigh the costs for the gas, for which reason the employment of nitrogen gas and carbon dioxide has not been motivated or been put to any appreciable use. Thus, there is a great need within the art for a cooled gas which can be obtained at reasonable cost.